Airfields are equipped with various types of lighting to guide aircraft during taxiing, take-off, and landing procedures. Several types of marker lights (e.g. runway edge lights, threshold lights, taxiway lights, etc.) are typically used, each with their own unique purpose. The marker lights may be grouped according to their location on the airfield and/or their purpose. The marker lights may also be portable, in that they may be moved from one location to another as circumstances warrant. The control of each group of marker lights may be handled by the control tower, which has the means to turn the marker lights on or off or to adjust the lights' intensity. Traditionally, this was accomplished by running wires from each group of marker lights to a central controller containing relays to control the power to each group of marker lights. Alternatively, each group of marker lights may be controlled by a local power relay, which in turn is remotely controlled using wires that run from the local power relay to a central controller. A disadvantage to these approaches is that multiple control and/or power cables from the marker lights to the controller are required. It may also be necessary to construct trenches in the ground to carry the cables from the marker lights to the controller.
Furthermore, some marker lights may need to be configured to illuminate sequentially or in some other pre-arranged order. For example, the marker lights may be required to illuminate in a sequence starting from the approach end of the airstrip and progressing toward the opposite end of the airstrip. This operation requires that the marker lights be controlled either individually or small groups, with each comprising one or more adjacent marker lights.
In certain applications, such as in remote or temporary airfields, the cost and/or time required to install the necessary wiring may be prohibitive. In some cases, installation costs may be reduced by using solar-powered marker lights. U.S. Pat. No. 6,573,659 to Toma et al., the contents of which are incorporated herein by reference, describes one such solar-powered lighting system. Although the use of a solar-powered lighting system would eliminate the need for power cables, cables would still be needed to transmit the control signals from the controller to the marker lights.
Controlling the operation of different groups of marker lights is especially difficult using portable marker lights. One approach is to pre-program each marker light with a specific group identity, which allows each marker light to be assigned as being a member of a specific group. However, there are several disadvantages with using pre-programmed group identities. First, after the group identities have been assigned to the marker lights, care must be taken during deployment to ensure that the marker lights corresponding to each group are placed in their correct locations. Second, since the group identities are pre-programmed, the number of marker lights in each group is pre-determined, thereby limiting flexibility during deployment.
In some deployment scenarios, such as in temporary airstrips, it is imperative to have rapid and straightforward deployment of marker lights, along with flexibility in the assignment of each marker light to one or more groups.
It is an object of the present invention to provide a method and system for assigning marker lights to separate groups and controlling their operation that overcomes the aforementioned disadvantages.
The objects of the invention will be better understood by reference to the detailed description of the preferred embodiment that follows.